1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * adv_swbutton.c - Software Button Interface Driver.
4 *
5 * (C) Copyright 2020 Advantech Corporation, Inc
6 *
7 */
8 #include <linux/kernel.h>
9 #include <linux/module.h>
10 #include <linux/input.h>
11 #include <linux/acpi.h>
12 #include <linux/platform_device.h>
13
14 #define ACPI_BUTTON_HID_SWBTN "AHC0310"
15
16 #define ACPI_BUTTON_NOTIFY_SWBTN_RELEASE 0x86
17 #define ACPI_BUTTON_NOTIFY_SWBTN_PRESSED 0x85
18
19 struct adv_swbutton {
20 struct input_dev *input;
21 char phys[32];
22 };
23
24 /*-------------------------------------------------------------------------
25 * Driver Interface
26 *--------------------------------------------------------------------------
27 */
adv_swbutton_notify(acpi_handle handle,u32 event,void * context)28 static void adv_swbutton_notify(acpi_handle handle, u32 event, void *context)
29 {
30 struct platform_device *device = context;
31 struct adv_swbutton *button = dev_get_drvdata(&device->dev);
32
33 switch (event) {
34 case ACPI_BUTTON_NOTIFY_SWBTN_RELEASE:
35 input_report_key(button->input, KEY_PROG1, 0);
36 input_sync(button->input);
37 break;
38 case ACPI_BUTTON_NOTIFY_SWBTN_PRESSED:
39 input_report_key(button->input, KEY_PROG1, 1);
40 input_sync(button->input);
41 break;
42 default:
43 dev_dbg(&device->dev, "Unsupported event [0x%x]\n", event);
44 }
45 }
46
adv_swbutton_probe(struct platform_device * device)47 static int adv_swbutton_probe(struct platform_device *device)
48 {
49 struct adv_swbutton *button;
50 struct input_dev *input;
51 acpi_handle handle = ACPI_HANDLE(&device->dev);
52 acpi_status status;
53 int error;
54
55 button = devm_kzalloc(&device->dev, sizeof(*button), GFP_KERNEL);
56 if (!button)
57 return -ENOMEM;
58
59 dev_set_drvdata(&device->dev, button);
60
61 input = devm_input_allocate_device(&device->dev);
62 if (!input)
63 return -ENOMEM;
64
65 button->input = input;
66 snprintf(button->phys, sizeof(button->phys), "%s/button/input0", ACPI_BUTTON_HID_SWBTN);
67
68 input->name = "Advantech Software Button";
69 input->phys = button->phys;
70 input->id.bustype = BUS_HOST;
71 input->dev.parent = &device->dev;
72 set_bit(EV_REP, input->evbit);
73 input_set_capability(input, EV_KEY, KEY_PROG1);
74
75 error = input_register_device(input);
76 if (error)
77 return error;
78
79 device_init_wakeup(&device->dev, true);
80
81 status = acpi_install_notify_handler(handle,
82 ACPI_DEVICE_NOTIFY,
83 adv_swbutton_notify,
84 device);
85 if (ACPI_FAILURE(status)) {
86 dev_err(&device->dev, "Error installing notify handler\n");
87 return -EIO;
88 }
89
90 return 0;
91 }
92
adv_swbutton_remove(struct platform_device * device)93 static void adv_swbutton_remove(struct platform_device *device)
94 {
95 acpi_handle handle = ACPI_HANDLE(&device->dev);
96
97 acpi_remove_notify_handler(handle, ACPI_DEVICE_NOTIFY,
98 adv_swbutton_notify);
99 }
100
101 static const struct acpi_device_id button_device_ids[] = {
102 {ACPI_BUTTON_HID_SWBTN, 0},
103 {"", 0},
104 };
105 MODULE_DEVICE_TABLE(acpi, button_device_ids);
106
107 static struct platform_driver adv_swbutton_driver = {
108 .driver = {
109 .name = "adv_swbutton",
110 .acpi_match_table = button_device_ids,
111 },
112 .probe = adv_swbutton_probe,
113 .remove_new = adv_swbutton_remove,
114 };
115 module_platform_driver(adv_swbutton_driver);
116
117 MODULE_AUTHOR("Andrea Ho");
118 MODULE_DESCRIPTION("Advantech ACPI SW Button Driver");
119 MODULE_LICENSE("GPL v2");
120
